"I met this guy who goes by the name of Memo and Chilango while we were being processed for deportation in Brownsville," the boy said in a statement to Mexican officials. "He told us he was from Houston and that he would give us $20 for every person we were able to cross."

Adult immigrant smugglers usually charge a lot more money to take people across the river, but they usually take them all the way to Houston, Garcia said.

"We can tell them apart from the immigrants because they usually carry cellular telephones and beepers," Garcia said.

The four minors arrested this week for immigrant smuggling would be sent to the Tamaulipas state district attorneys office in Matamoros, from where they'll likely be sent to a juvenile detention facility, Garcia said.